Using journalctl
The journalctl
utility is cool because it has so much flexibility. Let's start by looking at the various ways to search for and display log data. We'll do this on the Ubuntu machine because Ubuntu's persistent journald
logs will give us more to look at.
Searching for and viewing log data with journalctl
The simplest command for viewing log files is just journalctl
. As we see here, this will show you pretty much the same information that you'd see when you open a normal rsyslog
file in less
. You'll also see that the journalctl
output is automatically piped into less
:
donnie@ubuntu2004:~$ journalctl -- Logs begin at Tue 2021-01-05 20:46:55 EST, end at Tue 2021-08-10 14:23:17 ED> Jan 05 20:46:55 ubuntu2004 kernel: Linux version 5.4.0-59-generic (buildd@lcy01> Jan 05 20:46:55 ubuntu2004 kernel: Command line: BOOT_IMAGE=/vmlinuz-5.4.0-59-g> Jan 05 20:46:55 ubuntu2004 kernel: KERNEL supported cpus: Jan 05 20:46:55 ubuntu2004 kernel...